Fresco and wall painting
16. A chemical study of the paint medium in Roman wall paintings at Casa del Mitreo in Mérida showed presence of beeswax and soap, suggesting a wax-and-soap encaustic technique (José Cuní, Jorge Cuní. Consideraciones en torno a la técnica grecorromana de la encáustica, Archivo Español de Arqueología, 66 (1993), 110-112). A later study of those paintings using a very short extraction time for the binding medium, found absence of organic binders, stating that the paintings were executed with fresco. (M. J. Feliu, C. Fernández-Lorenzo, J. Martín. Spectroscopic analysis of Roman wall paintings from Casa del Mitreo in Emerita Augusta, Mérida, Spain. Talanta 59 (2003) 1119).